This invention relates to annular shaft seals of the type including continuous lip sealing elements. Such elements are disposed for sealing against oil flow through and between rotary shafts and associated housing bores, as in the case of a crankshaft and associated crankcase bore. More particularly, the invention relates to accommodation of radial shaft movements as associated with runout and misalignment eccentricities which typically cause premature failures in such seal systems.
There are numerous prior art annular shaft seal assemblies designed for accommodating shaft runout and misalignment in rotating shaft environments. Many of such assemblies provide for flexible sections which connect sealing elements with rigid case supports normally affixed to housing bores. The flexible sections afford a float capability to permit radial movement of a shaft relative to the rigid case support; however, the available systems fail to accommodate relatively extreme eccentricities over substantial periods of time.
In addition, most available prior art systems afford some type of garter spring arrangement about the rear surface of the lip sealing element body for effecting pressure to force the lip against the rotary shaft. Such systems do not, however, provide means for ensuring that the garter spring will remain in place during extreme radial movements of the associated crank shaft. Thus, improved flexible sections are desirable in order to enhance the eccentricity capacities to which the shafts may be subjected, and to provide means to retain garter springs about the rear surface portions of the continuous lip sealing elements under extreme eccentricity conditions.